A British soldier who was killed in southern Afghanistan on his 27th birthday was named by the Ministry of Defence tonight.

Lieutenant Douglas "Dougie" Dalzell, from Hamstead Marshall in Berkshire and a member of the 1st Battalion Coldstream Guards, died in an explosion in the Babaji area of Helmand province yesterday while carrying out a major operation against the Taliban.

In a statement his parents Anthony and Colette, brother Angus and sister Olivia paid tribute to Dalzell as a "true hero".

"Our darling son and brother to Olivia and Angus, you touched the hearts of so many. You are our world and we love you with all our hearts. You only ever looked for the good in people and kept strong and happy in all you did. You are a true hero and we will miss you forever," they said.

His commanding officer, Lieutenant Colonel Toby Gray, said Dalzell was killed "doing the job he loved and leading from the front".

He called the soldier "assured, confident, utterly professional and hugely popular with his men and held in the highest regard by his seniors".

He said: "It was clear to me that he adored his job and his guardsmen in equal measure... The gap he leaves in his company, the battalion and officers' mess is enormous.

"We all mourn his death and will miss his gentle yet keen sense of humour."

Fellow soldier Captain Jamie Russell also paid tribute. "Dougie was possessed of such a unique blend of professionalism and charm," he said.

"He shone throughout his short career and could always be trusted to do anything exceptionally well. His men responded by giving him their complete trust and they would have followed him anywhere. The regiment will be a darker place without this bright star."

Dalzell, who joined the army in 2007, was taking part in Operation Moshtarak, the largest offensive in Afghanistan since 2001.

The operation involves a combined force of 15,000 troops mainly from Britain, the US and Afghanistan and aims to free areas of Helmand province from Taliban control. It has suffered from stepped-up counter attacks since it began this month.

Lance Sergeant Dave Greenhalgh, 25, from Ilkeston, Derbyshire was the first soldier killed in the offensive. Another soldier who died yesterday has yet 'to be named.

Dalzell's platoon sergeant and close friend, John Amer, was killed last November.

Defence secretary Bob Ainsworth said he was "deeply saddened" to hear of the Dalzell's death.